JP3039217B2 - Consumable electrode arc welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a consumable electrode arc welding machine for performing welding by generating an arc between a consumable electrode and a base material.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional circuit configuration of a consumable electrode arc welding machine. 1 is a first DC power supply, 2 is a consumable electrode, 3 is a consumable electrode feeding device, 4 is a motor for feeding a consumable electrode, 5
Denotes an arc, 6 denotes a base material, and 7 denotes a start signal generation circuit. The activation signal generation circuit 7 generates a signal, the first DC power supply 1 and the consumable electrode feeding device 3 are activated, and when the consumable electrode 2 touches the base material, the output current rises, and the Joule heat causes the consumable electrode 2 to generate a current. We have adopted an arc start method in which the tip burns out and an arc is generated.

In the above conventional example, the feed speed of the consumable electrode 2,
By controlling the rise of the output current, an arc start success rate of about 90% can be obtained (see FIG. 6). However, the remaining about 10% of arc start failures lowers the operation rate particularly during automatic welding, and has become a bottleneck for FA. This was presumed to be caused by the fact that components of the consumable electrode contained in the consumable electrode adhered to the tip of the consumable electrode as slag (insulating material), so that no current was supplied to the consumable electrode.

To solve this problem, the present inventors have already considered the following invention. FIG. 9 shows the outline of the present invention.
This will be described with reference to FIG. In FIG. 9, reference numeral 8 denotes an arc generation detection circuit for detecting generation of an arc between the consumable electrode 2 and the base material 6, and 9 denotes a second DC which supplies a high DC voltage between the consumable electrode 2 and the base material 6. A power supply 11 is a rectifying element.

The operation will be described with reference to FIG. 9. A start signal generating circuit 7 generates a signal to a first DC power supply 1 and a second DC power supply 9, and both power supplies apply a DC voltage. Also
Since the second DC power supply 9 generates a high voltage , even if slag is present at the tip of the consumable electrode 2, the electric insulation caused by the slag can be destroyed and arc starting can be induced. Then, when the occurrence of an arc is detected by the arc occurrence detection circuit 8, the application of the second DC power supply 9 is canceled. According to the present invention, an arc start success rate of almost 100% can be obtained.

[0006]

In such a conventional consumable electrode arc welding machine, since a high DC voltage is applied, there is a problem of safety for a welding operator and peripheral equipment.

An object of the present invention is to provide a consumable electrode arc welding machine which solves the above-mentioned problems and has high safety and can obtain an arc start success rate of almost 100%.

[0008]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The present inventionofConsumable electrode arc welding machineHas the following configuration
You.

That is, the first consumable electrode arc of the present invention.
The welding machine supplies a first power between the consumable electrode and the base material.
A DC power supply, a consumable electrode feeding device for feeding a consumable electrode to the base material by a normal rotation start, a start signal generating circuit for starting a first DC power supply and starting the consumable electrode feeding device in a normal rotation, The consumable electrode feeding device applies a high DC voltage between the consumable electrode and the base material to the same polarity as the motor for feeding the consumable electrode and the first DC power supply for supplying power. A second DC power supply, a motor current detection circuit for detecting a current of the motor, and a first signal for generating a start signal to the second DC power supply when a signal output from the motor current detection circuit exceeds a predetermined value. And an arc detection circuit for detecting the occurrence of an arc and stopping the second DC power supply.

In order to further secure the first consumable electrode arc welding machine, the second consumable electrode arc welding machine of the present invention supplies electric power between the consumable electrode and the base material. A DC power supply, a consumable electrode feeding device for feeding a consumable electrode to the base material by a forward rotation start, and a start signal generating circuit for starting a first DC power supply to start the consumable electrode feed device in a normal rotation; Applying a high DC voltage between the consumable electrode and the base material to the same polarity as that of the motor for supplying the consumable electrode by the consumable electrode supply device and the first DC power supply. A second DC power supply, a motor current detection circuit for detecting a current of the motor, a consumable electrode reversing circuit for reversing the supply of the consumable electrode, and a consumable electrode reversing signal for sending to the consumable electrode supply device. Signal from the circuit or the signal from the start signal generation circuit A switching circuit for switching to any one of the motors, a signal is output to the switching circuit when the signal of the motor current detection circuit exceeds a predetermined value after the generation of a start signal, the consumable electrode is reversed, and the motor for reverse transfer of the consumable electrode is supplied. If the signal of the current detection circuit does not exceed the predetermined value, a second comparison circuit that outputs a signal to the switching circuit again to rotate the consumable electrode forward and output a start signal to the second DC power supply, An arc detection circuit for detecting the occurrence and stopping the second DC power supply.

[0011]

[0012]

According to the first consumable electrode arc welding machine of the present invention, when the slag is generated at the tip of the consumable electrode, the arc is not generated and the consumable electrode hits the base material to stop the feeding. Taking advantage of the fact that the motor in the consumable electrode feeder becomes overloaded and the motor current value increases, the second DC power supply is started only in this case, thereby making the conditions for high voltage application stricter. , To enhance safety.

Further, the second consumable electrode arc welding machine of the present invention reverses the supply of the consumable electrode when the motor in the consumable electrode feeder is overloaded, and performs the reverse transfer supply. If the current value of the consumable electrode feed motor is detected and the current value is larger than the predetermined value in the motor overload state, it is considered that the supply of the consumable electrode has stopped due to reasons other than the occurrence of slag, and a high DC voltage is applied. Conversely, if the current value of the consumable electrode feed motor is smaller than the predetermined value in the motor overload state, slag is generated at the tip of the consumable electrode, so that the arc is prevented from being generated with the base material and the consumable electrode Is considered to hit the base material, the supply of the consumable electrode is reversed again, and the normal supply state is applied, and then a DC high voltage is applied. It is.

[0014]

Embodiment ( Reference Example ) FIG. 1 is a view showing a reference example of the present invention. In FIG. 1, the same parts as those in FIGS. 8 and 9 are denoted by the same reference numerals, and description thereof will be omitted, and different points will be described. In FIG. 1, 10 is the first
The other parts are the same as those of the conventional example shown in FIGS.

In FIG. 1, a start signal generating circuit 7 includes a first
The DC power supply 1 and the consumable electrode feeding device 3 are activated, and after the first timer circuit 10 counts a predetermined time from the generation of the activation signal, the second DC power supply 9 is activated. When an arc is generated, the arc detection circuit 8 is activated. The second DC power supply 9 is stopped. As a result,
Since the second DC power supply 9 applies a high DC voltage between the consumable electrode 2 and the base material 6, the contact between the consumable electrode 2 and the base material 6 is prevented even if slag adheres to the tip of the consumable electrode 2. Induces discharge. The high DC voltage applied by the second DC power supply 9 is about 3
If it is above KV, a non-contact discharge is induced. FIG. 4 is a diagram showing the arc start success rates of the present invention and the conventional example. In addition, a high DC voltage is not applied between the consumable electrode 2 and the base material 6 at the same time when the start signal is generated, so that the safety for a welding operator and peripheral equipment is improved. FIG. 5 is a diagram showing the application timing of the DC high voltage in the first embodiment of the present invention.

(Embodiment 1 ) FIG. 2 is a view showing a first embodiment of the present invention. In FIG. 2, points different from FIG. 1 will be described, and description of the same points will be omitted. 2, reference numeral 12 denotes a second timer circuit, reference numeral 13 denotes a first comparison circuit, reference numeral 14 denotes a motor current detection circuit, and the other parts are the same as those in FIG.

In FIG. 2, a start signal generating circuit 7
The DC current source 1 and the consumable electrode feeding device 3 are activated, and the motor current detecting circuit 14 detects the consumable electrode motor current, the value of which is input to the first comparison circuit, and the feeding motor current is overloaded. When a predetermined value is exceeded, the second timer circuit 12
And after the second timer circuit 12 counts for a predetermined time,
The second DC power supply 9 is activated, and when an arc is generated, the arc detection circuit 8 stops the second DC power supply 9. As a result, FIG. 2 is the same as FIG. 1 in that a high DC voltage is applied. Therefore, the safety is higher for the welding operator and peripheral devices than in the case of the reference example . FIG. 6 is a diagram showing the application timing of the DC high voltage in the first embodiment.

(Embodiment 2 ) FIG. 3 is a view showing a second embodiment of the present invention. In FIG. 3, points different from FIG. 2 will be described, and description of the same points will be omitted. In FIG. 3, 15 is a switching circuit, 16 is a consumable electrode reversing circuit, 17 is a second comparison circuit,
Reference numeral 18 denotes a third timer circuit, and the other portions are the same as those in FIG.

In FIG. 3, a start signal generating circuit 7
The DC current source 1 and the consumable electrode feeding device 3 are activated, and the motor current detecting circuit 14 detects the consumable electrode feeding motor current, and the value is input to the second comparing circuit 17 so that the motor current is overloaded. When the value exceeds the value, the switching circuit 15 is switched to receive the signal from the consumable electrode reversing circuit 16 by the signal of the second comparison circuit 17, and the consumable electrode 2 is reversed,
When the motor current detection circuit 14 detects the consumable electrode feeding motor current and the value of the motor current at that time is smaller than a predetermined value of overload, the switching circuit 15 is switched again to the start signal generation circuit 7 and the second comparison is performed. The circuit 17 activates the third timer circuit 18, and after the third timer circuit counts for a predetermined time, activates the second DC power supply 9. When an arc occurs, the arc detection circuit 8 activates the second DC power supply 9. Stop. As a result, the second embodiment of the present invention the first embodiment of the first is the same in that applying a high DC voltage to the embodiment, the present invention for applying conditions become stricter in the present invention The safety of the DC high voltage is higher for the welding operator and peripheral equipment than in the case of the example. FIG. 7 is a diagram showing the application timing of the DC high voltage in the second embodiment of the present invention.

[0020]

According to the present invention, when a slag is generated at the tip of a consumable electrode, an arc is easily generated by applying a high DC voltage, and the start success rate is almost 100%. Is not easily applied.
Since the conditions are set, safety for workers and peripheral devices can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram in a reference example of the present invention.

FIG. 2 is a circuit configuration diagram according to a first embodiment of the present invention.

FIG. 3 is a circuit configuration diagram according to a second embodiment of the present invention.

FIG. 4 is a diagram showing arc start success rates of the present invention and a conventional example.

FIG. 5 is a diagram showing an application timing of a DC high voltage in a reference example of the present invention.

FIG. 6 is a diagram showing a DC high voltage application timing in the first embodiment of the present invention.

FIG. 7 is a diagram showing an application timing of a DC high voltage in a second embodiment of the present invention.

FIG. 8 is a circuit configuration diagram of a conventional machine.

FIG. 9 is a circuit configuration diagram already considered by the present inventors.

[Description of Signs] 1 First DC power supply 2 Consumable electrode 3 Consumable electrode feeder 4 Motor 5 Arc 6 Base material 7 Start signal generation circuit 8 Arc detection circuit 9 Second DC power supply 10 First timer circuit 11 Rectification Element 12 Second timer circuit 13 First comparison circuit 14 Motor current detection circuit 15 Switching circuit 16 Consumable electrode reversing circuit 17 Second comparison circuit 18 Third timer circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-180276 (JP, A) JP-A-49-44953 (JP, A) JP-A-62-68676 (JP, A) JP-A-63-1986 119981 (JP, A) JP-A-62-199269 (JP, A) JP-A-59-163082 (JP, A) JP-A-61-14079 (JP, A) Japanese Utility Model Showa 62-86972 (JP, U) Japanese Patent Publication No. 62-54585 (JP, B2) Japanese Patent Publication No. 38-4165 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/067 B23K 9/073 B23K 9/12 B23K 9/127

Claims (5)

(57) [Claims] A first DC power supply for supplying power between the consumable electrode and the base material; a consumable electrode feeding device for feeding the consumable electrode to the base material by starting the motor in a normal rotation; and a first DC power supply And a start signal generating circuit for starting the consumable electrode feeding device for normal rotation, a motor for feeding the consumable electrode by the consumable electrode feeding device, and a first DC power supply for supplying power. A second DC power supply for applying a high DC voltage between the consumable electrode and the base material with the same polarity, a motor current detection circuit for detecting a current of the motor, and a signal output from the motor current detection circuit Is greater than a predetermined value, a consumable electrode arc comprising: a first comparison circuit for generating an activation signal to the second DC power supply; and an arc detection circuit for detecting the occurrence of an arc and stopping the second DC power supply. Welding machine. 2. A first comparison circuit comprising a second timer circuit for generating a start signal to a second DC power supply after counting a predetermined time after a signal output from a motor current detection circuit exceeds a predetermined value. The consumable electrode arc welding machine according to claim 1 . 3. A first DC power supply for supplying power between a consumable electrode and a base material, a consumable electrode feeding device for feeding a consumable electrode to the base material by forward rotation start, and a first DC power supply And a start signal generating circuit for starting the consumable electrode feeding device for normal rotation, a motor for feeding the consumable electrode by the consumable electrode feeding device, and a first DC power supply for supplying power. A second DC power supply for applying a high DC voltage between the consumable electrode and the base material having the same polarity, a motor current detection circuit for detecting a current of the motor, and a consumable for reversing the supply of the consumable electrode An electrode reversing circuit, a switching circuit for switching a signal to be sent to the consumable electrode feeding device to either a signal from the consumable electrode reversing circuit or a signal from the starting signal generating circuit, and detecting the motor current after generating a starting signal. If the signal of the circuit exceeds the specified value, A signal is output to a switching circuit to reverse the consumable electrode, and if the signal of the motor current detection circuit at the time of reverse transfer supply of the consumable electrode does not exceed the predetermined value, a signal is output again to the switching circuit to output the consumable electrode. Consumable electrode arc welding, comprising: a second comparison circuit for rotating the first DC power supply and outputting a start signal to the second DC power supply; and an arc detection circuit for detecting generation of an arc and stopping the second DC power supply. Machine. 4. The consumable electrode according to claim 3 , wherein the second comparison circuit includes a third timer circuit that outputs a start signal to the second DC power supply after counting a predetermined time after outputting a signal to the switching circuit. Arc welding machine. 5. A consumable electrode arc welding machine according to any of claims 1 to 4 a second DC power supply is a DC power supply droop type.